<button> means put a button on the page and execute whatever is in the
<submit> submits a form.
If you want a button to sumbit your form, use the
onclick method of the button to do it. Why can't you use submit, though?
See here, they use a link
As @Arun says below, you can use:
<button type='submit'> inside your form, too. There are lots of ways to do things, so my only advice on top of this is to be consistent. I use
input out of habit, and that way I don't have a bunch of mixed conventions throughout my code.